Automobile accelerator pedals have, in the past, been linked to engine fuel subsystems by a cable, generally referred to as a Bowden cable. While such accelerator pedal designs varied, the typical return spring and cable friction together created a common and accepted tactile response for automobile drivers. For example, friction between the Bowden cable and its protective sheath reduced the foot pressure required from the driver to hold a given throttle position. Likewise, friction prevented road bumps felt by the driver from immediately affecting throttle position.
The mechanical cable-driven throttle systems, however, have been replaced with a more fully electronic, sensor-driven approach. With the fully electronic approach, the position of the accelerator pedal is read with a position sensor, which has been either of the contacting or non-contacting variety, and a corresponding position signal is made available for throttle control. The sensor-based approach has been especially compatible with electronic control systems in which accelerator pedal position is one of the several variables used for engine control.
Pedals including contacting position sensors have typically incorporated a potentiometer structure in the form of a rotor arm coupled to the pedal arm and adapted for rotation in response to rotation of the pedal arm and further adapted for contacting and sliding movement against the surface of a strip of resistive film located in the interior of the pedal.
The index position of the rotor arm has typically been set and locked with the use of metal pin that extends through the rotor arm and is fastened into the drum of the pedal arm.
The present invention is directed to a new, simple, cost-effective pedal assembly that includes a contacting position sensor, a hysteresis/friction generating assembly and alternatively also a kickdown assembly.
The present invention is also directed to a new assembly for setting and locking the index position of the rotor arm in a pedal with a contacting position sensor.